The SDN is a new network technology emerging in recent years, and its main characteristics include control and forwarding separation, network openness and programmability, as well as software and hardware separation. The SDN enables a conventional communication network equipment to be liberated from the dedicated hardware binding, thereby developing toward the direction based on a universal hardware platform plus customized software. The network function virtualization, network management simplification and network deployment automation are implemented through an open programmable interface. Thus, compared with conventional network function realization and engineering implementation, equipment cost and labor cost are greatly reduced, and deployment time is saved.
FIG. 1 is an architecture diagram of a software defined networking according to the related art. As shown in FIG. 1, the software defined networking technology is divided according to its architecture hierarchy, and is substantially divided into three layers from top to bottom: an application plane (or application layer), a controller plane (or controller layer) and a data plane or (datapath layer). At present, the industry discusses more about the controller layer and the datapath layer, and is being performing or has performed a large amount of standardization work, but the application layer and its internal structure, particularly how to perform application integration, management and control and how the services are orchestrated and interface with the controller layer, and the like, are discussed less and also developed relatively more slowly. This will cause deficiencies of capabilities of SDN in terms of usability, openness, programmability, manageability, operability, and the like, and disadvantages in healthy development of the SDN industry. In particular, there is a congenital obstacle on how to rapidly establish an SDN developer community and attract a large number of SDN application developers.
An application layer of the SDN currently defined by either the Open Networking Foundation (ONF) standard organization or the Open Day Light (ODL) open source organization is mainly positioned as providing highly abstract functions such as network applications and network service orchestration, etc. The application layer of the SDN may perform network resource application and service orchestration according to a user application request. In an uplink direction, the application layer of the SDN provides Application Programming Interface (API) call (arctic interface, also called application interface) with an external user in a Representational State Transfer (REST) manner, and a customized application function is realized for the external user, to realize a virtual network application function. In a downlink direction, the application layer of the SDN provides network API interface call (northbound interface) with an SDN controller in the REST manner and performs a resource application to the controller layer of the SDN to realize a virtual network service function.
At present, even from the point of the application layer of the SDN, most of its related technical discussions and standard work focus on an aspect of the northbound interface between the application layer of the SDN and the controller layer of the SDN. During a practical application of the SDN, the services provided by the SDN to the external side are mainly implemented through the interface of the application layer of the SDN and its external upper-layer application (i.e., arctic interfaces) and the orchestration function within the application layer of the SDN. At present, a functional requirement related to the arctic interface and a functional requirement related to the orchestration have not yet been fully excavated. Particularly, a specific functional architecture for network service orchestration and which specific functions should be provided have not yet been defined and perfected, which hinders integration of the SDN application and further influences development of the SDN application to a certain extent.
For the abovementioned problem of how to orchestrate SDN services by the application layer of the SDN, there is no related technology for reference yet.